This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Kawasaki disease (KD), a general vasculitis illness characterized by fever, mucocutaneous lesions and lymphadenopathy, is three times more prevalent in Hawaii than in the continental United States: 45 cases/100,000 children/year in Hawaii. Despite its high incidence, the etiology of KD is still unknown. Two weeks after diagnosis of KD, coronary artery abnormalities (CAA) can be demonstrated in up to 25% of the cases. The introduction of IVIG therapy had reduced the incidence of CAA to 8%. CAA may lead to myocardial ischemia later in life increasing the morbidity and mortality of KD. Therefore, diagnosing and adequately treating KD is crucial to preventing CAA and its long-term complications. The diagnosis of KD is based on clinical features, but in clinically incomplete presentations, CAA itself may be part of the diagnostic criteria according to the guidelines of the American Heart Association and the American Academy of Pediatrics. The gold standard method of detecting CAA is 2-dimensional echocardiography measuring the diameter of three coronary arteries: left main coronary artery (LMCA), left anterior descending artery (LAD) and right coronary artery (RCA). Normal values of coronary arteries in children and the detection of abnormalities were previously based on criteria constituted by the Japanese Ministry of Health. Instead of these age dependent values, de Zorzi et al introduced normal values and Z-scores (standard deviation from normal) based on the body surface area of children. Their study reported a much higher incidence of CAA associated with KD, especially in the early, febrile period of the illness. Fever, a general response to infectious and inflammatory processes, results in redistribution of blood circulation and vasodilation of specific vessels. Increased metabolic rate in fever demands higher cardiac output that requires increased coronary circulation. Thus, it can be hypothesized that fever itself may result in dilatation of the coronary arteries. What causes the specific vasculitis of the coronary arteries in a febrile illness like KD is yet to be determined. In this study we aim to compare the diameter of three coronary arteries in febrile and non-febrile children. The coronary artery measurements of hospitalized patients (6 months to 6 years old children) in a febrile period of their illness will be compared to coronary artery measurements of healthy non-febrile children, who previously underwent echocardiography. CAA will be determined according to de Zorzi's criteria. We will also determine the diameter of the coronary arteries of patients with Kawasaki disease in Hawaii and compare it to de Zorzi's standardized Z-score measurements. If the hypothesis, that fever itself may result in transient coronary artery dilatation, proves to be valid, the diagnostic criteria of incomplete KD may need to be revised.